Reconciliation of Total Reportable Segments Operating Income to Consolidated Income before Provision for Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Operating income	$ 6,222	$ 5,195
Equity in earnings of unconsolidated businesses	(5)	103
Other income and (expense), net	39	19
Interest expense	(537)	(685)
Income Before (Provision) Benefit For Income Taxes	5,719	4,632
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Operating income	(209)	(179)
Total Segments
Segment Reporting Information [Line Items]
Operating income	$ 6,431	$ 5,374